Experimental Validation of a Walking Model for Planar Bipeds With Curved Feet

Abstract

Bipeds with curved feet typically require less energy for walking than do point- or flat-footed bipeds, and they tend to mimic human gait more closely. Thus, understanding the effects of curved feet on bipedal walking gaits has the potential to improve both humanoid robot efficiency and human rehabilitation. This paper derives the equations of motion for planar bipeds with curved feet under the assumption, among others, of instantaneous transfer of support between the legs. The paper then verifies the mathematical model by comparing the results of simulation to previous experimental results for two very different bipedal robots — McGeer’s two-link, passive dynamic walker traversing a decline and the five-link, actuated biped ERNIE walking on a treadmill with a supporting boom. In both cases, the results from simulation match the experimental results very well despite the simplifying assumptions, indicating that the mathematical model captures the dominate dynamics of bipedal robots with curved feet.